1. Field of the Invention
The present invention relates to stirring apparatuses, and more particularly to a stirring apparatus for preventing an article to be stirred from foaming.
2. Description of the Prior Art
Concrete panels have been commonly used as a construction material. In recent years, there has been adopted a cellular concrete panel in order to utilize advantages of both concrete and wood such as the material quality of the concrete panel of the type as described, that is, one which, while being a concrete panel, is further rendered light in weight and satisfactory in heat insulating property.
There has been proposed the following process as a process of producing a cellular concrete panel. Firstly, steel in coil form for a framework is combined together lengthwise and crosswise to form a metal screen, and the outer periphery of this metal screen consisting of the steel bar in coil form is fixed to a frame. The framework thus formed is degreased, rinsed and immersed in a mortar liquid so as to be corrosionprotected, thereafter, set in a shuttering, then a slurry containing cement, an admixture, water and so forth is poured into this shuttering, the surface thereof is smoothed by means of a smoothing member, and temporarily cured for a certain period of time.
Upon completion of the temporary curing, the semi-product thus produced is removed from the shuttering. A plurality of such semi-products are put together and water-splashed in a pre-curing step, and thereafter, put into an autoclave where the semi-products are cured at high temperature and under high pressure. Upon completion of curing, the panels thus obtained are subjected to finish-coating and the like, and then, stocked as finished products.
In order to prevent a heavy-weight content contained in the mortar from settling in a mortar tank, into which a reinforcement-arranged frame for a concrete panel is immersed during the process of producing the concrete panels as described above, it is necessary to suitably effect the stirring operation. Apparatuses having screw-shaped rotor fins have been commonly used as the stirring means in the prior art. However, in that case, such a disadvantage has been presented that foams are easily formed in the mortar, whereby the corrosion protection effects for the reinforcement-arranged frame immersed in the mortar become less effectual. Additionally, a method of manually stirring the mortar, during which the foaming is tried to be controlled, is very low in the workability, and moreover, rather impracticable because the mortar is heavy in weight and stirred with difficulty. Therefore, necessity has been voiced for the provision of a stirring apparatus, wherein the foaming is prevented and the stirring is highly effectual.